1. Field of the Invention
The present invention relates to a unitable terminal fitting, a construction for uniting a plurality of terminal fittings and to a method for forming or assembling a unitable terminal fitting.
2. Description of the Related Art
Unitable terminal fittings are disclosed in Japanese Unexamined Patent Publication No. 11-67305 and are identified by the numerals 100 and 101 in FIGS. 12 and 13 herein. Each of the terminal fittings 100, 101 has a wire connecting portion 102 that can be connected with an end of a wire W and a shaft fixing portion 104 formed with an insertion hole 103 through which an unillustrated bolt is insertable. Engaging portions 105 and 106 are formed at opposite sides of the insertion hole 103 of each terminal fitting and are configured so that the engaging portions 105, 106 of one terminal fitting are engageable with the engaging portions 106, 105 of a mating terminal fitting. The two terminal fittings 100, 101 are united by sliding the shaft fixing portions 104 to align the insertion holes 103 with the engaging portions 105 located in the insertion holes 103 of the mating terminal fittings. The engaging portions 105, 106 of the two terminal fittings 100, 101 then are engaged and the terminal fittings 100, 101 are united with the insertion holes 103 aligned in thickness direction as shown in FIG. 13. The two terminal fittings 100, 101 then can be fixed to a specified location by one bolt.
The above-identified unitable terminal fittings 100, 101 enable no more than two wires W to be connected at one position. Thus, at least two fixing locations are required to fix three or more wires W.
In view of the above problem, an object of the present invention is to fix ends of three or more wires at one fixing location.
The invention is directed to a unitable or stackable terminal fitting with a wire connecting portion that can be connected with an end of a wire. The wire connecting portion is constructed so that a plurality of the terminal fittings can be placed one over another in the thickness or stacking direction of the terminal fittings. The stacked terminal fittings then can be united. The terminal fitting comprises first and second surfaces that are opposite to each other with respect to the thickness direction of the terminal fitting. The first and second surfaces each comprise engaging portions in the form of a projection and a recess configured so that the projection and recess on the first surface of one terminal fitting can engage the recess and projection on the second surface of a mating terminal fitting for holding the terminal fittings in a mated condition.
The wire connecting portion preferably is arranged so that the terminal fittings can be united with the wires substantially aligned.
Accordingly, ends of three or more wires can be placed one over another in thickness direction and can be united by the projections and recesses so that three or more wires can be fixed to one fixing location.
The terminal fitting is formed by bending a metallic plate material. The terminal fitting includes a shaft fixing portion for receiving a shaft to which the terminal fitting is to be fixed. The projection and recess are provided on exposed surfaces of outer layers at the front and rear sides of the shaft fixing portion where the metallic plate material is folded in three. The intermediate layer of plate material that is sandwiched between the two outer layers is held in close contact with the outer layers.
The shaft is fixed to a specified fixing location and is fixed to the shaft fixing portions of the engaged terminal fittings. The projections and recesses need to have a specified engagement margin in the thickness direction to be engageable in the thickness direction of the terminal fittings. The projections and recesses conceivably could be provided where the metallic plate material of the terminal fitting is folded in two. However, the two folded sections of the metallic plate material cannot be held in close contact to provide the engagement margin. Accordingly, a specified clearance has to be defined between the two folded sections of the metallic plate material. Thus, the clearance between the two folded sections can be squeezed by a compressive force in the thickness direction of the terminal fitting that acts when the terminal fitting is mounted on the shaft at the fixing location. However, even if such a compressive force acts, such a compressive force cannot squeeze the clearance between the exposed surfaces of the subject terminal fitting because the intermediate portion is held in close contact between exposed surfaces.
The shaft fixing portion preferably is formed by folding the metallic plate material at least in two, and mutually engaged assembling portions are provided at folded sections of the metallic plate material for preventing the folded sections of the metallic plate material of the shaft fixing portion from getting loose. The two bent portions preferably are in contact with each other at least via one or more contact projections. Accordingly, the folded sections of the metallic plate material of the shaft fixing portion are prevented from getting loose.
The wire connecting portions of the respective terminal fittings are located alternately at a first arranged position and at a second arranged position that is displaced in an offset direction from the first position. Thus, the wires do not interfere when the terminal fittings are united as compared to a case where the wire connecting portions are arranged at the same position.
Guide means preferably are provided for guiding the projections and recesses into engagement.
The projections and recesses preferably can be brought into engagement by moving them at an angle and preferably a right angle to a direction of mounting of the unitable terminal fitting to a shaft.
The projections and/or recesses preferably comprise a positioning edge that projects toward a shaft insertion hole so as to conform to the shaft.
The invention also is directed to a construction for uniting a plurality of terminal fittings to be fixed by one shaft. At least one unitable terminal fitting is an intermediate terminal fitting that is to be located at an intermediate position of the plurality of terminal fittings. Each of end terminal fittings located at the opposite ends of the plurality of terminal fittings along thickness direction comprises the wire connecting portion, the shaft fixing portion, one projection and one recess.
The intermediate terminal fitting preferably comprises a wire connecting portion to be connected with an end of a wire and a shaft fixing portion through which the shaft is insertable. Projections and recesses are provided around the shaft fixing portion on front and rear surfaces that face mating terminal fittings and are engageable with recesses and projections of the mating terminal fittings for holding the terminal fittings united.
Accordingly, the end terminal fittings located at the opposite ends in thickness direction are each provided with only one projection and recess. Thus, the united terminal fittings fixed by the shaft are held in surface contact at its shaft side and its fixing location. Therefore, the terminal fittings can be fixed stably.
Preferably, at least one end terminal fitting is provided with a turn-stop portion for preventing a turning of the terminal fitting(s).
The invention also is directed to a method for forming or assembling unitable terminal fittings. Each terminal fitting has a wire connecting portion for connection with an end of a wire. The wire connecting portion is constructed such that a plurality of the terminal fittings can be united while being placed one over another in the thickness direction of the terminal fittings. The method comprises providing a projection and a recess on each of the opposite first and second surfaces of the terminal fitting. The method may then comprise uniting the terminal fitting with a mating terminal fitting by engaging the respective recess and projection on the second surface of the respective mating terminal fitting.
The method may further comprise bending a metallic plate material to form the terminal fitting, providing the projections and recesses on a pair of exposed surfaces at sides of the shaft fixing portion where the metallic plate material is folded in three, and holding the plate material between the two exposed surfaces to serve as an intermediate portion held in close contact with the respective exposed surfaces.
The method may further comprise forming assembling portions at folded sections of the metallic plate material for preventing the folded sections of the metallic plate material that form the shaft fixing portion from getting loose.
These and other objects, features and advantages of the present invention will become more apparent upon reading of the following detailed description of preferred embodiments and accompanying drawings. It should be understood that even though embodiments are separately described, single features thereof may be combined to additional embodiments.